Stringed musical instruments, such as guitars, violins, cellos, pianos and harpsichords are constructed almost entirely of wood. Wood construction has been necessary for the well established reason that the reasonance and impedance qualities of wood are the critical factors in the quality of sound which radiates from the instrument. Heretofore, various wood substitutes have been advanced or suggested for all or part of the wood normally used in stringed instruments. For the most part, however, all such substitutes have resulted in instruments suffering one or more defects such as misplaced resonance frequencies and overall weak response.
Unfortunately, a large number of the instruments of wood manufactured today are of inferior quality which can be attributed in good part to the lack of skilled craftsmen. To compensate the variations in wood properties to properly and individually place the resonance frequencies necessary to produce consistently fine instruments requires skills possessed by very few persons. Moreover, the mechanical and physical properties of wood are greatly affected by climatic conditions, especially humidity. Some wood instruments undergo drastic changes in quality with even the slightest variation in environmental conditions. Cracking, to name one major disadvantage, is common with instruments made of wood.
Not the least in importance is the fact that the worldwide supply and accessability of suitable wood for any purpose is dwindling. Heretofore, a relatively inexpensive durable wood substitute, stable with changes in environmental conditions and having predictable properties suitable for the construction of musical instruments possessing a musical quality as good as or better than instruments made of wood has not been known in the art.
In stringed instruments, the entire body, including the top and back plates or case, the ribs, the enclosed air, and all of the attachments, form a highly complex vibrating system. Numerous materials have been suggested and advanced as substitutes for wood in the manufacture of top and back plates or sounding boards. Among the substitutes known in the art are glass epoxy-balsa sandwiches, aluminum-aluminum honeycomb sandwiches, solid glass foam and beryllium, to name a few. While experimentation with the foregoing materials has represented scientific advancement, none of the wood substitute materials heretofore suggested, or used, have successfully duplicated or exceeded the qualities of wood in the construction of stringed instruments.
It is also well known that the overall shape and material constituents of stringed instruments are properties which cannot be treated independently. If, for example, isotropic materials such as metals, ceramics, and plastics were used and an attempt made to duplicate the sound radiating qualities of wood, the instruments would be of such bizarre shapes as to be unplayable.